PJC-1 / log-parser

Building a log parser with Python

Learning how to use Python by building a log parser.

Setting up the app

Install pipenv with the command:

pip3 install pipenv

Create the virtural environment for the project. From within the project directory. Run the command:

pipenv shell

This will create a Pipfile, which will hold all your project's dependencies.

Install the dependencies. From within the project directory. Run the command:

pipenv install flask flask-sqlalchemy flask-marshmallow-sqlalchemy

After the dependencies have finished installing, you can check the Pipfile, it should look like this:

[[source]]
name = "pypi"
url = "https://pypi.org/simple"
verify_ssl = true

[dev-packages]

[packages]
flask = "*"
flask-sqlalchemy = "*"
flask-marshmallow = "*"
marshmallow-sqlalchemy = "*"

[requires]
python_version = "3.6"

Create an app.py file, which will hold the server side code. From within the project. Run the command:

touch app.py

From the app.py file, import dependencies and modules:

from flask import Flask, request, jsonify
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow
import os

Initialize the application and run the server

# Init app
app = Flask(__name__)

# Run Server
if __name__ == '__main__':
   app.run(debug=True)

To run the server, from the terminal run the command:

python app.py

If successful, the terminal output should look like the following:

$ python app.py
* Serving Flask app "app" (lazy loading)
* Environment: production
  WARNING: This is a development server. Do not use it in a production deployment.
  Use a production WSGI server instead.
* Debug mode: on
* Restarting with stat
* Debugger is active!
* Debugger PIN: 268-311-121
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

Here is an example of how to create a route to GET json data with flask:

@app.route('/', methods=['GET'])
def get():
   return jsonify({ 'msg': 'Hello world'})

If we use an API tool such as Postman and test the url http://localhost:5000, we should receive the following response:

{
   "msg": "Hello world"
}